Artificial ski surface unit



FIG. 1 is a top plan view of an artificial ski surface unit showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a side view thereof; and

FIG. 6 is a view of the other side thereof. 

The ornamental design for an artificial ski surface unit, as shown and described. 